I had removed a transform manager job folder by hand from
C:\inetpub\media\Transform Manager\Smooth (VC1)\Configuring
and then it kept on showing it in IIS Manager, under Transform Manager / Job Monitor / Queued and right click on the job there and selectin Cancel froze IIS Manager badly. Rebooting the machine and starting the manager would freeze it again when trying to expand the top server name node in the IIS Manager.
the only way to fix it was to copy another queued job folder and rename the copy to take the name of the job folder I had deleted (found the name from the log [see below]).
btw the 1st error logged seems to be cause I left empty the field that sends HTTP notifications on job progress (not sure what I should enter there - I guess this should be a warning?)
2012-09-07 19:21:30.6576 Error Failed to submit job for watch folder Video files to VC-1 Smooth Streams. Manifest name: C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E\20120907114826_66D948454CA446C083CFBC695610B42E.smil. Error: Object reference not set to an instance of an object..
2012-09-07 19:21:30.6732 Error Exception while processing jobs in job manager Video files to VC-1 Smooth Streams. Exception message: Object reference not set to an instance of an object.
2012-09-07 19:21:30.6732 Error Exception while processing jobs in job manager Video files to VC-1 Smooth Streams. Exception message: Object reference not set to an instance of an object.
2012-09-07 19:23:25.9574 Error Failed to move files from C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E to C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Canceled\20120907114826_66D948454CA446C083CFBC695610B42E. Exception message: Could not find a part of the path 'C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E'.
2012-09-07 19:23:26.9714 Error Failed to move files from C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E to C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Canceled\20120907114826_66D948454CA446C083CFBC695610B42E. Exception message: Could not find a part of the path 'C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E'.
2012-09-07 19:23:28.9838 Error Failed to move files from C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E to C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Canceled\20120907114826_66D948454CA446C083CFBC695610B42E. Exception message: Could not find a part of the path 'C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E'.
2012-09-07 19:23:31.9946 Error Failed to move files from C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E to C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Canceled\20120907114826_66D948454CA446C083CFBC695610B42E. Exception message: Could not find a part of the path 'C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E'.
2012-09-07 19:23:36.0038 Error Failed to move files from C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E to C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Canceled\20120907114826_66D948454CA446C083CFBC695610B42E. Exception message: Could not find a part of the path 'C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E'.
2012-09-07 19:23:41.0114 Error Failed to move files from C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E to C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Canceled\20120907114826_66D948454CA446C083CFBC695610B42E. Exception message: Could not find a part of the path 'C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E'.
2012-09-07 19:23:47.0175 Error Failed to move files from C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E to C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Canceled\20120907114826_66D948454CA446C083CFBC695610B42E. Exception message: Could not find a part of the path 'C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E'.
2012-09-07 19:23:54.0219 Error Failed to move files from C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E to C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Canceled\20120907114826_66D948454CA446C083CFBC695610B42E. Exception message: Could not find a part of the path 'C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E'.
2012-09-07 19:24:02.0247 Error Failed to move files from C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E to C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Canceled\20120907114826_66D948454CA446C083CFBC695610B42E. Exception message: Could not find a part of the path 'C:\inetpub\media\Transform Manager\Smooth (VC1)\WorkQueue\Configuring\CLIPS\20120907114826_66D948454CA446C083CFBC695610B42E'.
...
...
kept on logging this at different times
This is quite bad behaviour:
1) the IIS Manager should be more resilient against pluggins freezing it
2) the Transform Manager should be more resilient against file system issues and not freeze like that when trying to Cancel a non-existent job (its folder missing for good or temporarily). User should be given an option there to try again, cancel, or consider the job as invalid and throw it away from internal settings or something